Dividend Yield Question

I'm looking for information on historic annual dividend yields for multiple corporations and was curious if there are any resources online that provide this information for the past 10 or so years?

Additionally, when calculating the annual dividend yield for a company that pays dividends quarterly, would the most correct approach be to take the dividend yield paid each quarter, divide by the share price on the ex-dividend date, then add the quarterly yields together for the annual yield?

Thanks!